I've downloaded the latest version of calibre, but every time that I click on the .exe file, nothing happens. I've tried waiting for more than thirty minutes, and I've tried uninstalling calibre and then trying to install it again, but that was a really bad move, since now I don't have the program at all in my computer.

I've even tried installing the older version of calibre that I still had, but then that file started acting up and won't start up either.

Please help! I love using this program and would really like to get it up and running again.

I'm using a Windows Vista Home Edition laptop, and my user account has administrator privileges.